Basic knowledge of batteries

Electric Battery Fundamentals

What is meant by electric battery and its uses?

An electric battery is a device that consisting of one or more electrochemical cells with external connections provided to power electrical devices such as flashlights, mobile phones, and electric cars. All batteries are made up of three basic components: an anode (the '-' side), a cathode (the '+' side), and some kind of electrolyte (a substance that chemically reacts with the anode and cathode). In addition, nominal voltage, capacity and C-Rate are the main indicators of batteries. It is a device that stores chemical energy and converts it to electrical energy. The chemical reactions in a battery involve the flow of electrons from one material (electrode) to another, through an external circuit. The flow of electrons provides an electric current that can be used to do work.

When a battery is supplying electric power, its positive terminal is the cathode and its negative terminal is the anode, and the electrode materials are irreversibly changed during discharge is the primary batteries, while secondary (rechargeable) batteries can be discharged and recharged multiple times using an applied electric current.

Electric Battery Types

What are different types of battery?

Batteries are classified into Non-rechargeable batteries (primary batteries) and Rechargeable batteries (secondary batteries).

Primary batteries, or primary cells, can produce current immediately on assembly. They are made of electrochemical cells whose electrochemical reaction cannot be reversed. In other words, primary batteries are “single use” and cannot be recharged. A common primary battery is the dry cell. Examples are zinc–carbon (Leclanché) cells, alkaline zinc–manganese dioxide cells, and metal–air-depolarized batteries. Primary lithium cells are now available.

Secondary batteries, also known as secondary cells, must be charged before first use, which means that the original chemical conditions within the cell can be restored by passing current to flow into it: that is, by charging from an external source. Examples of secondary batteries include nickel-cadmium (NiCd), lead acid, and lithium ion batteries. Fuel cells are similar to batteries in that they generate an electrical current, but require continuous addition of fuel and oxidizer.

In addition, many types of electrochemical cells have been produced, with varying chemical processes and designs, including galvanic cells, electrolytic cells, fuel cells, flow cells and voltaic piles.

There are a lot of different battery types, all with their own applications, characteristics and construction. This page lists the different battery types which are described on the batteries guide.

Electric Battery Applications

How are batteries used today?

Batteries play numerous important roles in everyday life, from providing the initial power needed to start the engines of cars to acting as a backup source of electricity in telecommunications, public transportation and medical procedures. They power our wristwatches for months at a time. They keep our alarm clocks and telephones working, even if the electricity goes out. They run our smoke detectors, electric razors, power drills, mp3 players, thermostats, laptop and smartphone -- and the list goes on. 

These portable power packs are so prevalent, it's very easy to take them for granted. But the fraction of the stored charge that a battery can deliver depends on multiple factors, including battery chemistry, the rate at which the charge is delivered (current), the required terminal voltage, the storage period, ambient temperature and other factors.

Battery systems offer the convenience and reliability to keep the lights on for hours, days, weeks or years. They work automatically to keep your house powered through grid brownouts and blackouts. This category contains pages explaining various battery applications.